The study aimed to explore the effect of group dynamic assessment on word learning through lexical inferencing and to compare it to that of vocabulary enhancement exercises. Through purposive sampling, 45 intermediate EFL learners were selected as participants and randomly assigned to three groups. The participants read six texts over a 6-day period and answered comprehension questions for each text. In the second phase of each treatment session, the first group engaged in lexical inferencing of the underlined words within group dynamic assessment framework. The second group did two vocabulary exercises for each target word. The third group engaged in lexical inferencing of target words through group dynamic assessment framework and also did one vocabulary exercise for each target word. Vocabulary Knowledge Scale (Wesche and Paribakht in Can Mod Lang Rev 53:13-40, 1996) was used to measure learners' knowledge of the target words 1 day prior to the treatment and 1 day and 28 days after the treatment. The results showed that in terms of gains in depth and size of vocabulary knowledge the first and the second groups were not significantly different. However, the third group significantly outperformed the first and the second groups. It was concluded that group dynamic assessment is as effective as vocabulary exercises in enhancing word learning through lexical inferencing and that the combination of group dynamic assessment and vocabulary exercises could enhance word learning through lexical inferencing even more.